


Resonance

by Domenika Marzione (domarzione)



Category: Captain America (Movies), Iron Man (Movies), Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Engineer Tony Stark, Friendship, Gen, Recovery, Team
Language: English
Status: Completed
Published: 2015-10-13
Updated: 2015-10-13
Packaged: 2018-04-26 05:44:48
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,260
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4992550
Author URL: https://archiveofourown.org/users/domarzione/pseuds/Domenika%20Marzione
Summary: <blockquote class="userstuff">
              <p>Tony's reasons for helping Bucky Barnes can be entirely attributable to general do-gooderism and a love of science. (Because he really, really hates it when people rub his personal growth in his face.)</p>
            </blockquote>





	Resonance

**Author's Note:**

> Inasmuch as I used a ‘reference’ for Bucky here in terms of recovery level, it was the version from [Blues in the Groove](http://archiveofourown.org/works/3585333), which I suppose this could be a prequel for. Reading that is completely unnecessary for this, though.

Tony offers to help Rogers find Barnes, of course he does. It's what friends should do -- and he and Rogers are becoming friends, despite both of their best efforts -- and Tony has done a lot more for people he respects a lot less. He doesn't care that Barnes was a HYDRA assassin any more than he cares that Clint was briefly Loki's minion or that Clint killed people even when he wasn't under mind control or that Natasha has killed even more. He's a former arms dealer and has a great big glass house from which he knows not to throw stones.

"I'm not saying that the very concept of him doesn't scare the crap out of me," he tells Pepper privately. "And I don't just mean the 'world's deadliest assassin' part. But whoever's left of James Barnes deserves better than what he's gotten."

Pepper kindly does not mention that this was not exactly the quality or quantity of grace he showed Rogers when it was time to dig him out of the ice. He never likes it when his personal growth is rubbed in his face.

Neither of them are surprised when he spends most of the next week waking up in the middle of the night sweating and shouting in Pashto. His own experiences in Afghanistan don't measure up to Barnes's seventy years of captivity, but there's a fair bit of 'there but for the grace of God go I' involved. Different injuries, different reasons to be kept, different means of doing so... and yet. _And yet._ Bad people found them and took them and tried to use them to reshape the world and it resonates in the bone.

But even if that resonance has him offering to help Rogers, and then waiting for Rogers to accept said offer, it doesn't mean that he's going to go gallivanting around the globe hunting a ghost. He delegates that task to JARVIS, setting up several programs to run in case Barnes isn't familiar with modern passive surveillance technology. (He is.) But while he can't find Barnes in anything close to real time, he can find Barnes in the way that might matter more. With JARVIS's heavy lifting, he can compile enough video evidence to establish that Barnes is, in fact, _Barnes_ and not the Winter Soldier running in stealth mode. There are fragments of audio long enough to hear him saying "excuse me" and being particular about a lunch order and there are close-ups of expressions and gestures that are very human and nothing like the soulless footage from DC. Tony gets JARVIS to whittle it down to one Bucky Barnes Supercut and that's what he shows to Rogers.

Once upon a time, he might've wished he could make Captain America cry. It would have worked out a lot of teenaged angst and resentment and Daddy Issues. But now that he's actually done it, he's proud of himself for entirely different reasons. Rogers doesn't bawl or anything, just sits there with tears streaming down his smiling face while Tony pretends to be doing other things. And so while Tony later jokes out loud about how Rogers appreciates this more than the millions of dollars and R&D man-hours Tony has put into the Avengers, privately he understands. Or he thinks he might; he has never lost everything as irretrievably as Rogers has, but he has had enough shit happen to him to maybe appreciate the power of seeing something (someone) significant survive.

It comes out far less elegantly when he tries to explain it to Pepper, but she understands the gist of it.

Barnes doesn't want to be found until he does, at which point he saves Steve the frequent flier miles and turns up on the doorstep. Tony's in California when it happens, going over the plans to rebuild the house in Malibu that he so thoughtlessly got destroyed. (He's letting Pepper do what she wants this time, saying he only wants twelve percent for his own space.) He gets a text from Bruce that says "the eagle has landed" and Tony honestly thinks it's about Bruce's latest experiment until he gets a photo from Romanov of Barnes and Rogers talking to Maria Hill in what is very clearly Rogers's living room.

"So how do you feel about adding to your nascent collection of assassins?" Tony asks Pepper, who looks cautiously concerned - he's brought worse home - before she sees the picture and then smiles.

"He's a handsome one," she says. "Steve looks happy. We should keep him."

Keeping Barnes is easier said than done. Hill and Romanov handle the initial part, which mostly boils down to doing whatever they have to to keep Rogers from grabbing Barnes and disappearing because he thinks someone's going to throw his BFF in a prison without a door. Nobody's doing anything to Barnes besides feeding him and getting him some clean clothes, however, which only does so much to calm Rogers down.

"It's a little charming and a lot 'I want to shoot him,' Romanov tells Pepper on speakerphone. "It's a good thing Sam is local now."

By the time Tony does get back to New York, Rogers has eased off the protectiveness and gotten back to doing Captain America work and Barnes has submitted to medical and psychological evaluation and is sitting with Hill spilling seventy years of terrible secrets. There are therapists involved as well - for Rogers as well as the trauma specialist Wilson dug up for Barnes - and it's all very modern for their resident Twentieth Century Boys. Tony's in favor of therapy for everyone; talking to someone whose job is to actually listen to you is very satisfying, bonus if they can sort out your problems for you. And everyone has known Rogers has been a bottle rocket of sadness waiting to explode, so if someone can put their liberal arts degree to good use and defuse him, all the better.

Barnes in the flesh, by the time Tony meets him, is nothing at all like what Tony imagines him to be for more reasons than that he's been to a barber and is wearing a pair of chucks. He's not the tragic young hero Tony remembers from his own childhood, the one his father used to call a 'damned fine soldier' in his drunken reminisces. He's not the Winter Soldier, silent specter of death. He's not the platonic ideal of a friend Rogers has dedicated his life to finding. He's a man, surprisingly intact for all of the trauma that's been inflicted upon him, but whose scars clearly show. If Tony had to summarize him in a word, that word would be "exhausted."

Barnes spends most of his time with Hill reliving his past, with Rogers probably doing the same, in therapy definitely doing the same, or out in the city wandering around, presumably because it's the only place he can go to escape his past. (If Hill had any illusions that Barnes wasn't aware that he was being tracked on his perambulations, the first time he waved to a CCTV camera on the street popped that balloon.) He tags along when Rogers shows up for the mandatory team social events, quiet but not silent and perfectly sociable when spoken to. But everyone is a little afraid to speak to him because what topic is safe with a man who has only known war and death and pain for so long?

(Food. Food is safe. The World's Mightiest Heroes spend a lot of time talking about umami.)

The first time Tony spends any time with Barnes alone is in his lab at the Tower, a carefully-arranged appointment because Barnes thinks something might be wrong with the arm. Tony has seen the specs and the imaging they did when Barnes first came in, has spent days poring over the admittedly-ingenious design, but he's never looked at it up close except for whatever is poking out of Barnes's sleeve. Which is just as well because even from across the room, it's transfixing; the elegance of the form, yes, but Tony can't get the suits to display that kind of fine motor control. The precision of the arm allows Barnes to use it completely naturally and without the kind of side-eye supervision amputees usually have to keep on their prosthetics. Pepper tells Tony to stop drooling.

"What can I do you for?" he asks when Barnes appears, hesitating by the open door. "You losing functionality or hearing something?"

Pepper calls Tony's lab his playroom, which is how he thinks of it, too. But it's a lab and he honestly doesn't know how hard it is for Barnes to be in a space like this. Tony's got posters on the walls and plastic toys on the benches and it looks completely unprofessional as far as a workspace goes, but that might not matter. Tony couldn't go into dark places for months after he got back from Afghanistan without breaking into a cold sweat and all that had happened to him had been involuntary life-saving surgery.

Barnes pushes off the door jamb with clear force of effort and comes into the room. He stops halfway, holding out his left arm. "It's warm," he says with a frown. "Warmer than it should be."

The arm is air-vented, but there is a coolant system that runs through it. If that's on the fritz, it would explain any temperature variation. Barnes nods when Tony explains that out loud, letting him scan the arm again. There is a two degree difference -- "your arm has a slight fever" -- but nothing structurally different from the earlier scans.

"Let me think on this for a day or two," Tony says, since this is not going to have an obvious answer and Barnes looks like he wants to flee. "You're not in any pain, right?"

"Nah," Barnes assures and Tony thinks that he's telling the truth. "Just don't want it blowing up or anything. It's off warranty, you know?"

It takes Tony the better part of a week to stumble upon the answer and, when he does, it's at the worst possible moment. He's pro mod drag-racing in New Mexico, strapped in and waiting for the flag to drop, when it hits him.

"JARVIS, what're they using for a coolant in Barnes's arm?"

The answer is available by the time he crosses the finish line (first, his superior chassis design overcoming his distraction): they don't know. It's a closed system, it wasn't booby trapped, and nobody has actually poked around inside Barnes's arm.

"So riddle me this," Tony begins as he hops up on to the stool in Bruce's lab back in New York the following Tuesday. "If you're going to run coolant through fine machinery that is exposed to extreme temperatures, what would you use?"

Bruce looks up from his microscope. "You remember those conversations we keep having about what I am and am not qualified to talk about like an expert?"

"I have the original and the remix on my iPod," Tony assures, since the question had been rhetorical. Bruce used to bring his car, back when he had one, to Jiffy Lube. "The coolant in Barnes's arm was presumably chosen to fit the conditions he was exposed to as the Winter Soldier: it had to be able to handle the cryofreeze without changing state. How well it worked at room temperature was probably less important, so long as it did work."

He hops off the stool because he thinks better in motion. "But if Barnes is going to be living his life outside the tube, we need to optimize the coolant along different parameters. And possibly the delivery system. Hrmm."

He doesn't realize he's left Bruce hanging until he's back in his lab and Pepper is reminding him that they have a dinner party to go to and it's five hours later. "Bruce said you walked into his lab, mumbled something about antifreeze and Bucky Barnes, then walked out again," she says in the limo uptown. "Should I be concerned? And should Bucky?"

"It wasn't antifreeze and Barnes is the instigator, not the unwitting victim," he assures, which only partially pacifies Pepper because she knows him. "He came to me about the arm. I think I know what we have to do."

What they have to do is figure out what exactly is running through Barnes's pseudo-vein and then do some tests to see what work better. How efficiently they'll be able to work will depend on how okay Barnes is with anyone working on the arm. Which is why it's a 'we.' Tony has all of the engineering know-how to master the arm, but Rogers or someone else is going to have to be there to deal with the non-cybernetic parts of Barnes. Tony leaves the others to handle that, instead doing an extra read-through of the scans and images because he's not going to have much wiggle room to feel his way through this procedure. This can't be exploratory - he has to get it right the first time.

Barnes professes indifference to Tony poking around inside his arm, but Tony's still glad Rogers insists on hanging out as he does the test to see exactly what HYDRA was using as coolant. And not just because the first time Tony sees Barnes without a shirt on, he wants to retch. Yinsen had little better than diner cutlery to crack open his chest and his own scarification isn't half as bad. The prosthetic interface at Barnes's shoulder is so appallingly crude it appears willfully done; it's savage and medieval and considering how much delicate neuro-mechanical interfacing is underneath, it's a mockery. Rogers has obviously seen it before, but he grimaces at the sight. Barnes doesn't look at it, but it's out of familiarity, not horror.

Once they get started, Barnes remains calm, but Tony doesn't miss the white knuckles on Barnes's right hand as he samples the coolant. "If you can hold out for another twenty minutes, we'll get the heat sensors in now and this way, we won't have to open it back up until we've got a solution."

It takes more like thirty-five minutes and Rogers telling a convoluted story about how the Boston Braves ended up in Atlanta, but all of the sensors are placed perfectly. "What this is going to do is let me see exactly how much heat each part of your arm is generating," Tony tells Barnes. "And how efficiently - or not - your cooling system is dealing with it. Once we get enough data, we'll figure out what to use and whether or not there's a more efficient way to use it. Because if we have to go in there, we might as well do it right the first time."

He shows Barnes and Rogers the readings on one of the HUDs and lets them watch it as Barnes does basic activities with his arm. It seems to put them both at ease a little, so Tony leaves them to it while he sets up the vial of coolant in the spectrometer. He loses track of them as he gets more involved in the logistics of rerouting the coolant path and when he looks up, they're gone.

He had originally planned on taking a week's worth of data to form his conclusions, but it ends up being closer to two weeks because Fury sends them news about a HYDRA base in Greenland and they come back with weapons specs that he wants to work on right away because if HYDRA has them built, it's trouble. (They don't have them built, or if they do, they don't work. It's a design flaw that comes from being too clever, which is both harder to resolve for HYDRA but more worrisome long term for the Avengers.) Barnes comes alone to get the sensors taken out and there are no white knuckles and it's less stressful for Tony because of it.

"The good news is that, structurally, we can work with what you've got - it really is the most efficient system," he tells Barnes as he works. "But flushing out the coolant and replacing it with the new one is not going to be a quick like an oil change in a car. These are not compounds that want to be anywhere near each other. We're going to have to drain the system, flush it out completely, and then fill it up again. You're going to need to be hooked up to a temporary heatsink so we don't fry anything while it's offline. It'll be a day-killer."

Barnes makes a face. "Do I have anywhere else I have to be?"

The answer is no, but that's also not really the point, which Tony thinks Barnes understands.

The procedure, when it happens, happens in a room with a view of Central Park and a projection television. Bruce suggested the change in location - no reason to keep Barnes trapped in the lab all day - and the logistics aren't that more complicated than a portable dialysis setup. Barnes is parked in a lounger, attached to the heat sink and the drain, and left with JARVIS oudoing Netflix. Tony monitors the progress remotely for the most part, only turning up to initiate each new phase of the process. Barnes isn't alone very much; Rogers is there for most of it, Barton and Bruce for some of it. It's probably more extended socializing than Barnes has done since he arrived and nobody jokes that it's because Barnes is effectively tied down. The vibe is low-key, but more hanging-out than hospital visit. There's pizza and bahn mi and whatever Barton got from the Pakistani place on Tenth and _Blazing Saddles_ is playing when Tony comes in to test the completeness of the air flush.

"They're one joint away from a college dorm," he tells Hill when she calls in to find out how things are going.

The new coolant works like it's supposed to and Barnes's arm is actually three degrees cooler than it had been, five than it had been running before the swap. "It feels weird," Barnes admits, touching his left arm with his right hand. "I'll get used to it."

Tony calls Rhodey after Barnes leaves and they talk about nothing in particular for an hour that includes long silences with nothing but tapping keys; Rhodey is doing paperwork at the Pentagon and Tony is fiddling with HYDRA's bomb specs and it's nothing like when they used to sit in Tony's dorm at MIT and do problem sets together, but it kind of is. It's comfortable having someone familiar to speak in shorthand with, to not even focus your attention on and just know that they're there. And the tiny corner of Tony's brain that deals with interpersonal skills is aware that this is what Rogers has been missing since he woke up and he feels... it's not pity. Rogers doesn't want any and Tony doesn't consider it anything worth giving. But maybe it's gratitude for what he has for himself, what he has managed to not squander or lose through indifference or simple bad behavior, what he has possibly even earned. And if he can give a little bit of that to Rogers (and Barnes), then good.

And then he changes his mental radio station because he doesn't like to examine his personal growth any more than when Pepper does it.

"Hey, so I'm racing in North Carolina next month, you wanna make a weekend out of it?"

**Author's Note:**

> [A notice for this fic was posted to tumblr](http://laporcupina.tumblr.com/post/131092978499/for-your-writing-prompt-possibly-something-fun) if you'd like to like or reblog there.


End file.
